296 
SCANDINAVIAN FISHES. 
The pores belonging to the system of the lateral line 
are small, and in old specimens hardly distinguishable. 
The pectoral tins and the disk of the ventral tins 
are of the same structure and shape as in the preceding 
genus; but the former are not so broad — their upper 
angle lying lower down, and the number of rays being 
only 20 — and are without the incision in the lower 
posterior part of the margin. The distance between 
the pectoral tins at the bottom is scarcely equal to the 
diameter of the eye; when laid back, the tins do not 
extend to the vent, the length of their upper part in 
full-grown specimens being 14 or 15 % (13*8 — 15*1 %) 
of the length of the body. In specimens from the 
Baltic, however, the length of these tins is relatively 
greater (17 — 19 %), and also in young specimens: 
in specimens between 24 and 28 mm. long we have 
found them to measure 17 '5 — 17 "8 % of the length of 
the body. They are also, as a rule, longer in the male 
than in the female. The length of the oval disk formed 
by the ventral tins is also relatively greater in young 
specimens than in old and, generally, in the male than 
in the female, its longitudinal diameter, including the 
dermal rim, varying in adult specimens between about 
147 2 and 1 9 1 / 2 % of the length of the body, and in young 
specimens between 20 and 2l7 2 thereof. In the hind 
part of the dermal margin we find the tips of the four 
posterior (inner) rays on each side". In the old males, 
which are furnished with a genital papilla behind the 
vent, the latter lies about half-way between the ad- 
hesive disk and the anal fin; while in young specimens 
and the females it generally lies nearer the latter. Hence 
it follows, as a rule, that the length of the pectoral 
fins in young specimens and those from the Baltic (see 
above) is greater than the distance between the vent 
and the anal fin, but in the adult Atlantic specimens less. 
The first dorsal fin, with from 6 to 8 simple, but 
soft, spinous rays, is covered in old specimens, as we 
have mentioned above, by the more or less cartilaginous 
hump 6 , which develops during growth. This hump 
generally rises almost evenly from the occiput or forms 
a slight break at its origin; but sometimes, especially 
in old males, it may rise like a cock’s-comb, or at least 
in a sharply marked semicircle, to a height equal to 
the depth of the head at the occiput or that of the 
body at the termination of the abdominal cavity. The 
alteration in the shape of the body thus caused is so 
great that Pallas and his successors long believed that 
the young specimens were a distinct species ( Cyclopterus 
minutus, Plate XVI, the three middle figures). Fries 
was the first to demonstrate that these young examples 
belong to the species now under consideration, in spite 
of their rounded back and distinct anterior dorsal fin, 
with visible rays' 5 . At this period, before the rows of 
tubercles appear, the skin is also smooth; and some- 
times, as v. Duben and Koren have shown, specimens 
30 mm. long may be “entirely smooth and even, with- 
out the least trace of tubercles, spines or ridges”. For 
a long time, too, the tips of the last rays in the first 
dorsal fin may be distinguished, though not with ease; 
this seems to be most persistent in specimens from 
the Baltic. 
The second dorsal and the anal fins are very like 
each other, the first (simple and unarticulated) and the 
last (articulated and generally simple) rays being the 
shortest, and the fourth (the first branched) ray the 
longest. The remainder of the margin is rounded or 
almost straight. The base of the former fin, the length 
of which varies between 15 and 20 % of that of the body, 
and undergoes greater increase with age, even relatively 
than the length of the anal fin, is always longer than 
that of the latter, which varies between about 14 and 
1 5 7 2 % of the length of the body. During youth the 
height of each of these fins is equal to its base; in 
old specimens, on the other hand, the height of the 
anal fin is greater than the length of its base, but in 
the second dorsal fin the proportions are reversed. 
Specimens from the Baltic are apparently marked by 
the still more considerable height of these fins (more 
than 18 % of the length of the body), and hence it 
follows that in their case, even in old specimens as 
a According to Bloch ( Fische Deutschl., Ill, p. 104), Hanow estimated that the adhesive power of the disk in a Lump Sucker 8 
Prussian inches (21 cm.) long represents a lifting-power of 7 4 1 / ;J Zollpfund (34 8 / 10 kgrm.). Pennant states ( Brit . Zool ., Ill, p. 118) as a 
proof of this power that he once placed a fish of this species, just caught, in a pail containing several gallons of water, and by taking hold 
of the tail of the fish was able to lift pail, water and fish without forcing the latter to relinquish its hold of the bottom. It is, however, 
the adhesion of the disk alone, without any special exertion on the part of the fish, that is at work here, for Buckland {Nat. Hist. Brit. 
Fish., p. 126), on cutting off the adhesive disk of a dead Lump Sucker 5 kgrm. iu weight, and pressing it against a damp window-sill, 
found that it was only with the greatest effort he could just lift it straight up, though laterally it did not offer the slightest resistance. 
6 A similar formation appears during the spawning-season in the males of the Pacific Salmons. 
e Even Ascanics, however, had seen and identified these young specimens, though his figure of one of them (1. c.) is not very instructive. 
